1. Field of the Invention
The present invention relates to a contents' relationship visualizing apparatus, a contents' relationship visualizing method and its program.
2. Description of the Related Art
Many contents are utilized in these days along with the development of information communicating techniques. On the other hand, there is a need to grasp a configuration of a contents' set made of many contents for improving retrievability of the contents. The configuration of the contents' set can be grasped by defining a relationship between the contents.
The method for defining a relationship between contents employs a method based on contents' attributes (such as genre, creator and creation timing) or a method based on contents' usage histories. However, since the method based on attributes needs to input attributes for each content, its usability may lower if the contents' set is on a large scale.
On the other hand, since the method based on usage histories has only to acquire usage histories, its usability rarely lowers in general even if the contents' set is on a large scale. The method based on usage histories can define a relationship between contents in consideration of contents' usage situations irrespective of existing attributes' classification.
For example, in Japanese Patent Application Laid-Open No. 2002-342375 described later, a relationship between contents is defined on the principle that “when the same user accesses multiple contents, the contents are in a certain relationship.” The strength of the relationship between the two contents is defined by the number of users utilizing both the contents, that is, the co-occurrence frequency.